Post-operative pain inhibitor for hip joint replacement and method thereof

ABSTRACT

A post-operative pain inhibitor system comprises a controller and leads. Neuro-stimulator circuitry may be included within the patient controller or within one or more prosthetic components for generating a signal. In one example, a hip implant includes a prosthetic component having at least one electrode where the at least one electrode is configured to deliver energy pulses. Topical leads, percutaneous leads, subcutaneous leads, intraosseous leads, or leads can be placed in proximity to the operative field corresponding to the prosthetic component installation. The lead or electrodes can be coupled to neuro-stimulation circuitry to stimulate peripheral nerve fibers to affect body generated action potentials. A transmitter or power source can be housed in a prosthetic hip component. Controller can modify the pulse width, pulse shape, pulse repetition rate, and pulse amplitude of the signal thereby allowing the patient to adapt the signal to minimize their perceived pain.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. application Ser. No.12/604,099 filed on Oct. 22, 2009 claiming priority benefit of the U.S.Provisional Patent Applications No. 61/196,916, U.S. Provisional PatentApplication No. 61/196,915, and U.S. Provisional Patent Application No.61/196,914 all filed on Oct. 22, 2008, the entire contents of which arehereby incorporated by reference.

FIELD

The invention relates in general to pain treatment in living organisms,and particularly though not exclusively, is related to post-operativepain reduction after joint replacement.

BACKGROUND

Implantable devices are becoming more prevalent. Complex mechanical andelectrical systems such as pacemakers, heart defibrillators, orthopedicimplants, neurological devices are but a few of the systems beingimplanted on a common basis. Implantable devices have proven reliableand are placed inside the human body for extended periods. Orthopedicimplants are typically used to repair a damaged joint or bone in askeletal system. Orthopedic surgery comprises at least one incision toaccess the joint region. In a complete joint replacement, bone is cut inthe joint region and the articulating surfaces of the joint arereplaced.

Pain is a substantial issue associated with joint implantation. In fact,knee replacement is known to be one of the most painful surgeries to thepatient. Pain is controlled both pre-operatively, intra-operatively, andpost-operatively. Narcotic medication is still a widely used choice tocontrol pain in a complete joint replacement. Narcotic pain controlvaries from patient to patient. The patient response to the medicationcan have side effects such as nausea, vomiting, itching, ileus,confusion, respiratory problems, and depression to name a few. Ingeneral, these side effects can affect patient recovery both short termand long term.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of present invention will become more fullyunderstood from the detailed description and the accompanying drawings,wherein:

FIG. 1 is an illustration of a pain modulation system for post-operativepain treatment of a skeletal system in accordance with an exemplaryembodiment;

FIG. 2 is an anteroposterior view of a leg in accordance with anexemplary embodiment;

FIG. 3 illustrates an anteroposterior view of a post-operative paininhibitor system 100 for post-operative pain treatment of the skeletalsystem in accordance with an exemplary embodiment;

FIG. 4 is a lateral view of a post-operative pain inhibitor system inaccordance with an exemplary embodiment;

FIG. 5 illustrates an anteroposterior view of a post-operative paininhibitor system 100 for post-operative pain treatment of the skeletalsystem in accordance with an exemplary embodiment;

FIG. 6 is a lateral view of post-operative pain inhibitor system inaccordance with an exemplary embodiment;

FIG. 7 is an illustration of a prosthetic component having integratedelectrical leads to provide a signal to a peripheral nerve fiber toreduce post-operative pain;

FIG. 8 is an illustration of components of a post-operative paininhibitor system integrated into more than one prosthetic components;

FIG. 9 is a lateral view of post-operative pain inhibitor system inaccordance with an exemplary embodiment, additionally FIGS. 10 and 11illustrate additional exemplary embodiments, FIG. 10 illustrates a hipprosthesis in accordance with an exemplary embodiment and FIG. 11illustrates a tibial implant in accordance with an exemplary embodiment;

FIG. 12 is an illustration of a femoral implant and cup implant inaccordance with an exemplary embodiment; and

FIG. 13 depicts an exemplary diagrammatic representation of a machine inthe form of a computer system within which a set of instructions, whenexecuted, may cause the machine to perform any one or more of themethodologies discussed above.

DETAILED DESCRIPTION

The following description of exemplary embodiment(s) is merelyillustrative in nature and is in no way intended to limit the invention,its application, or uses.

Processes, techniques, apparatus, and materials as known by one ofordinary skill in the art may not be discussed in detail but areintended to be part of the enabling description where appropriate. Forexample specific computer code may not be listed for achieving each ofthe steps discussed, however one of ordinary skill would be able,without undo experimentation, to write such code given the enablingdisclosure herein. Such code is intended to fall within the scope of atleast one exemplary embodiment.

Additionally, the sizes of structures used in exemplary embodiments arenot limited by any discussion herein (e.g., the sizes of structures canbe macro (centimeter, meter, and greater in size), micro (micro meter),nanometer size and smaller).

Notice that similar reference numerals and letters refer to similaritems in the following figures, and thus once an item is defined in onefigure, it may not be discussed or further defined in the followingfigures.

In all of the examples illustrated and discussed herein, any specificvalues, should be interpreted to be illustrative only and non-limiting.Thus, other examples of the exemplary embodiments could have differentvalues.

In general, the successful implantation of a device in an organism andmore specifically in a joint or spine depends on multiple factors. Onefactor is that the surgeon strives to implant the device to obtainadequate alignment of the extremity or spine. A second factor is properseating of the implant for stability. A third factor is that orthopedicimplants typically comprise more than one component that are aligned inrelation to one another. A fourth factor is balance of loading over arange motion. A fifth factor and a more general factor that relates toall implanted devices is to minimize infections that can occurpost-operatively. A sixth factor is post-operative pain. Implant surgerycan result in substantial pain to the patient. Pain can affect thequality of life of the patient and increase the time for rehabilitation.

A post-operative pain Inhibitor (PPI) is described herein below thatintegrates peripheral nerve inhibition in the local post-operative fieldof the implanted joint. The PPI is a pain modulation system that can beused in conjunction with the skeletal system and more specifically withan artificial joint implantation. For illustrative purposes, a kneeimplant and a hip implant are used to show the operation of the paininhibitor system. A knee implant is known for being one of the morepainful implant surgeries. In general, the PPI is used to alleviate painrelated to the skeletal system and can be used for joint implants suchas, but not limited to, knee, hip, shoulder, spine, ankle, wrist,prosthetic devices, articulating, and non-articulating bone structures.

FIG. 1 is an illustration of a post-operative pain inhibitor system 100for post-operative pain treatment of a skeletal system. In anon-limiting example, a lateral view of a leg is illustrated after aknee replacement surgery has been performed. At least one incision inskin 1 is used to expose the joint region. The incision gives access toa femur 2 and a tibia 1. A knee prosthesis or joint implant 10 typicallycomprises a femoral implant, an insert, and a tibial implant. A distalend of a femur 2 is prepared and receives the femoral implant. In a fullknee replacement, the femoral implant has two condyle surfaces thatmimic a natural femur. The femoral implant is typically made of a metalor metal alloy. Similarly, a proximal end of tibia 3 is prepared toreceive the tibial implant. The tibial implant is a support structurethat is fastened to the proximal end of tibia 3 and is usually made of ametal or metal alloy. An insert is fitted between the femoral implantand tibial implant. In the full knee replacement, the insert has twobearing surfaces in contact with the two condyle surfaces of the femoralimplant that allow rotation of the lower leg under load. The tibialimplant retains the insert in place. The insert is typically made of ahigh wear polymer that minimizes friction.

Post-operative pain inhibitor system 100 comprises a controller 32coupled to topical leads 27 and percutaneous leads 25. System 100 canaddress pain control during and after joint replacement. Pain affects apatient's recovery and hinders early joint function. Common effects ofpain following total knee replacements include depression, tachycardia,insomnia, reflex muscle spasm and sometimes chronic regional painsyndromes. Research has shown that pre-operative pain control has apositive effect on the severity of pain post-operatively.Intra-operative anesthetic control is critical. Narcotic medication isstill needed for joint implants and especially for total kneereplacements. Pain control is variable and the common side effects(nausea, vomiting, itching, ileus, confusion, respiratory depression)often interfere with rapid recovery. Post-operative pain inhibitorsystem 100 can reduce reliance on other pain control methods or be usedin conjunction with the methods to deliver a more consistent and higherlevel of pain reduction.

In at least one exemplary embodiment, one or more leads are placed inproximity to the operative field of the implanted joint. Controller 32is shown connected by wire to topical lead 25 and percutaneous leads 27.Controller 32 provides a signal to leads 25 and 27. Leads 25 and 27 areused to transfer pulses of electrical energy to stimulate peripheralnerve fibers to inhibit or block a pain signal thereby reducing theperceived pain by the patient. Either type of lead may be used, or bothtypes may be used in combination, to achieve adequate pain control.

In general, a low amplitude current is used to stimulate the peripheralnerve fibers. Topical lead 27 and percutaneous leads 25 are currentinjecting components that receive a signal from controller 32. Topicalleads 27 are placed on a surface of skin 1 to make electrical contact.Percutaneous leads 25 include a contact region that punctures or couplesthrough the outer skin layer to make contact. Leads 25 and 27 areattached to a predetermined position on the patient's body which istypically in the vicinity, but not limited to the operative field wherethe orthopedic device was implanted and a peripheral nerve fiber.

The lateral view of the leg illustrates two embodiments of a wiredelectrical connection from neuro-stimulator circuitry of controller 32to stimulate peripheral nerves for the inhibition of pain. A firstembodiment comprises a placement of topical leads 27 with a wiredconnection to controller 32. The second embodiment is the placement of apercutaneous lead 25 with a wired connection to controller 32. In bothcases the electrical pulses travel through external wires to terminatein the lead affixed to the patient's skin 1. In the case of the kneeimplant, leads 25 and 27 are shown contacting skin 1 in proximity to theimplanted knee. Leads 25 and 27 provide an electrically conductivecontact to the skin in which to direct the current to the peripheralnerve fiber. The low amplitude pulsed current provided by theneuro-stimulator circuitry of controller 32 blocks the propagation ofbody generated action potentials.

Pain signals are carried by small, slow conducting peripheral nervefibers (C-fibers). The pain signals can be blocked by stimulation of thelarge diameter, rapidly conducting peripheral nerve fibers (A-fibers).The balance between A and C-fibers determines the degree of pain.Stimulation of A-fibers by a variety of stimuli (scratching, pressure,vibration, or electrical stimulation) with little or no stimulation ofC-fibers will close the gate. Thus, controller 32 in conjunction withleads 25 and 27 stimulate the A-fibers with a current pulse to close thegate and block the propagation of pain signals carried by the C-fibersthereby reducing perceived pain by the patient.

In at least one exemplary embodiment, a bipolar electrode device can beused to electrical contact skin 1 and deliver a signal to inhibit a bodygenerated pain signal propagating in a peripheral nerve fiber. Thebipolar electrode device corresponds to leads 25 and 27. The bipolarelectrode device has an anode and a cathode. In a non-limiting example,the anode of the bipolar electrode device is placed in close proximityto the peripheral nerve fiber and the operative field. The cathode ofthe bipolar electrode device is placed away from the anode in a regionof low sensitivity. Sufficient energy is provide by controller 32 tohyperpolarize the peripheral nerve fiber.

Alternatively, a tri-polar electrode device can be used to selectivelyblock the propagation of body generated action potentials travelingthrough a nerve bundle. The tri-polar electrode device corresponds toleads 25 and 27. The tri-polar electrode device comprises a first anode,a second anode, and a cathode. In a non-limiting example, the cathode isplaced between the first and second anodes. A pulse is provided to theperipheral nerve fiber from both anodes. The cathode can be placednon-equidistant between the anodes. The signals provided by each anodecan be different. The tri-polar electrode generates a uni-directionalaction potential to serve as collision block with body-generated actionpotentials representing pain sensations in the small-diameter sensoryfibers of a peripheral nerve fiber.

In at least one exemplary embodiment, controller 32 is accessible to thepatient. It should be understood that each patient is different and eachwill have varying ability to cope with pain. Furthermore, placement ofthe leads 25 and 27 and the conducting distance will also vary. In anon-limiting example, controller 32 couples to a belt that can bewrapped and held at the waist of the patient. Controller 32 includescontrols such as dials, switches, a keyboard, a touch panel, touchscreen, or a wireless interface. The controls on controller 32 are usedto modify the signal provided to leads 25 and 27. The controls ofcontroller 32 are coupled to a logic unit, a signal generator, a powersource, and communication circuitry to generate electrical impulsestailored to an individual's need for appropriate pain relief in terms ofpulse frequency, pulse width, and pulse amplitude. Thus, a signalprovided by system 100 can be tailored for the individual. Controller 32can include a digital signal processor, a microprocessor, amicrocontroller, logic circuitry, and analog circuitry to generate theappropriate signal. The post-operative pain inhibitor (PPI) comprisingcontroller 32 and leads 25 and 27 integrates electrically mediated painrelief and can be controlled by the patient and modify the pulseamplitude, width, wave shape, repetition rate, and zone migrationfrequency as it relates to their pain threshold. In at least oneembodiment leads 25 or 27, or other sensing structures in contact withthe patient's body, can be a device to monitor perspiration, heat,modify impulses to affect swelling, EMG integration, and monitorinflammatory markers.

FIG. 2 is an anteroposterior view of a leg in accordance with anexemplary embodiment. The anteroposterior view illustrates positioningof the post-operative pain inhibitor system 100 in relation to the leg,operative field, and joint implant 10. Controller 32 is attached by abelt to the patient. Controls of controller 32 are easily accessible tothe patient to modify the signals output by neuro-stimulator circuitryresiding therein. Topical leads 27 and percutaneous leads 25 areelectrically coupled to skin 1 to provide a signal to peripheral nervefibers. Topical lead leads 27 are attached and positioned in proximityto femoral implant 12 on both the medial and lateral sides of the knee.Percutaneous leads 25 includes a point that punctures the skin (forbetter contact) and are positioned in proximity to tibial implant 14 onboth the medial and lateral sides of the knee. Topical leads 27 andpercutaneous leads 25 are within the operative field of the implantedjoint. Both types of leads 25 and 27 can be used to transfer pulses ofelectrical energy and stimulate peripheral nerve fibers to inhibitpropagation of body generated action potentials related to pain. Asshown, leads 25 and 27 are connected to controller 32 by a wire.Controller 32 outputs electrical pulses that travel through the externalwires to an attachment point on each of leads 25 and 27. Controller 32is portable and can be powered by a wired power supply, battery,rechargeable battery, or other powering scheme. The portability allowsthe patient to actively use post-operative pain inhibitor system 100during a rehabilitation process.

FIG. 3 illustrates an anteroposterior view of a post-operative paininhibitor system 100 for post-operative pain treatment of the skeletalsystem in accordance with an exemplary embodiment. The anteroposteriorview illustrates positioning of the post-operative pain inhibitor system100 in relation to the leg, operative field, and joint implant 10.Controller 32 is attached by a belt to the waist of the patient.Controls of controller 32 are easily accessible to the patient to modifythe signals output by neuro-stimulator circuitry residing therein.Subcutaneous leads 26 underlie skin 1 and can be positioned close toperipheral nerve fibers to enhance the efficacy of pain modulation.Subcutaneous leads 26 can be placed in the tissue during theimplantation of femoral implant 12 and tibial implant 14 respectively tofemur 2 and tibia 3. The surgeon can view the operative field and mapthe region for optimal placement of subcutaneous leads 26 resulting inlower power utilization and better pain control. In a non-limitingexample, leads 26 are shown positioned in proximity to femoral implant12 on both the medial and lateral sides of the knee and in proximity totibial implant 14 on both the medial and lateral sides of the knee.

In at least one exemplary embodiment, a transmitter/receiver 43 is usedto communicate to controller 32 and subcutaneous leads 26.Transmitter/receiver 43 is in a housing affixed to skin 1 in proximityto leads 26. Transmitter/receiver 43 can include neuro-stimulatorcircuitry to generate a signal for blocking propagation of bodygenerated action potentials. In at least one exemplary embodiment,controller 32 is in wireless communication with transmitter/receiver 43.Controller 32 includes an interface to allow the patient to adjust thepulse amplitude, width, wave shape, repetition rate, and zone migrationfrequency in conjunction with transmitter/receiver 43. Alternatively,transmitter/receiver 43 can be wired to controller 32.Transmitter/receiver 43 radiates pulses of electrical energy to animplanted conductor with one or more subcutaneous leads 26 positioned inthe vicinity of femoral implant 12 and tibial implant 14 to provideeffective peripheral nerve stimulation. In an alternate embodiment, ahub 45 can be affixed to the patient's skin 1. Hub 45 is directlyconnected to an implanted conductor with one or more subcutaneous leads26 positioned in the vicinity of femoral implant 12 and tibial implant14 to provide effective peripheral nerve stimulation.

FIG. 4 is a lateral view of post-operative pain inhibitor system 100 inaccordance with an exemplary embodiment. The lateral view illustratespositioning of the post-operative pain inhibitor system 100 in relationto the leg, operative field, and joint implant 10. Controller 32 isattached by a belt to the waist of the patient. Controls of controller32 are easily accessible to the patient to modify the signals output byneuro-stimulator circuitry residing therein. Subcutaneous leads 26underlie skin 1 and can be positioned close to peripheral nerve fibersto enhance the efficacy of pain modulation. In a non-limiting example,leads 26 are shown positioned in proximity to femoral implant 12 on boththe medial and lateral sides of the knee and in proximity to tibialimplant 14 on both the medial and lateral sides of the knee. In anon-limiting example, leads 26 are shown positioned in proximity tofemoral implant 12 on both the medial and lateral sides of the knee andin proximity to tibial implant 14 on both the medial and lateral sidesof the knee.

FIG. 5 illustrates an anteroposterior view of a post-operative paininhibitor system 100 for post-operative pain treatment of the skeletalsystem in accordance with an exemplary embodiment. Controller 32 isattached by a belt to the waist of the patient. Controls of controller32 are easily accessible to the patient to modify the signals output byneuro-stimulator circuitry residing therein. In at least one exemplaryembodiment, system 100 includes an addition of intraosseous leads 22 toenhance the efficacy of pain modulation. Intraosseous leads 22 arerespectively coupled to femur 2 and tibia 3. In a non-limiting example,intraosseous leads 22 can be attached to or inserted in bone during theimplantation of an orthopedic joint. In general, intraosseous leads 22are attached to bone of the skeletal system in proximity to a peripheralnerve fiber.

In at least one exemplary embodiment, topical leads 27 can includetransmitters to radiate pulses of electrical energy to implantedintraosseous leads 22. Topical leads are connected by wire to controller32. Topical leads 27 are placed in proximity to intraosseous leads 22.More specifically, one or more topical leads 27 having transmitters arepositioned on skin 1 of the patient in proximity to the distal end ofthe femur 2 where a first intraosseous lead 22 resides. Similarly, twoadditional topical leads 27 having transmitters are positioned on theskin 1 of the patient in proximity proximal end of tibia 3 where asecond intraosseous lead 22 resides. Each topical lead 27 radiatespulses of electrical energy to an implanted conductor within intrasseousleads 22. The pulsed electrical energy is received by intraosseous leads22 and conducted within the bone to create an operative fieldstimulating the peripheral nerve fiber to block propagation of bodygenerated action potentials corresponding to pain. The patient canchange or modify the signal provided to intraosseous leads 22 bymodifying pulse amplitude, pulse width, wave shape, repetition rate, andzone migration frequency using controller 32 thereby affecting perceivedpain to the patient and tailoring the signal for the individual.

Alternatively, intraosseous leads 22 can include a transmitter/receiverand a power source such as a battery. An external powering coil couldalso be used to energize intraosseous leads 22 or to recharge thebattery. Intraosseous leads 22 can be in wireless communication withtopical leads 27 or controller 32. Using low amplitude current pulses toblock the body generated action potentials system 100 could be operatedover a significant period of time.

FIG. 6 is a lateral view of post-operative pain inhibitor system 100 inaccordance with an exemplary embodiment. The lateral view illustratespositioning of the post-operative pain inhibitor system 100 in relationto the leg, operative field, and joint implant 10. Controller 32 isattached by a belt to the waist of the patient. Controls of controller32 are easily accessible to the patient to modify the signals output byneuro-stimulator circuitry residing therein. Intraosseous leads 22 areattached to femur 2 and tibia 3 close to peripheral nerve fibers toenhance the efficacy of pain modulation. In a non-limiting example,leads 27 are shown positioned in proximity to the distal end of femur 2and proximal end of tibia 3 on both the medial and lateral sides of theknee. Controller 32 is in wired communication with topical leads 27while topical leads are in wireless communication with intraosseousleads 22 as described hereinabove.

FIG. 7 is an illustration of a prosthetic component having integratedelectrical leads to provide a signal to a peripheral nerve fiber toreduce post-operative pain. In a non-limiting example, the prostheticcomponent is femoral implant 12. In general, a distal end of femur 2 isprepared and shaped to receive femoral implant 12. In at least oneexemplary embodiment, a profile of femoral implant 12 is shaped similarto existing implants being offered such that the device can be installedusing procedures and practices known to the surgeon. Although shown asfemoral implant 12, the principles and structures described herein canbe applied to a wide range of orthopedic prosthesis as well as otherimplanted medical devices.

An antereoposterior view of femoral implant 12 is shown. Theillustration is viewed towards the condyle surfaces of femoral implant12. Circuitry 44, within or underlying peg lugs 19 is coupled with leads20 through an electrical interconnect. In an non-limiting example, theinterconnect can be wire, flex interconnect, or other suitableelectrically conducting material. The interconnect connects from peglugs 19 to leads 20. Leads 20 are exposed on the surface of theprosthetic component. Leads 20 are positioned around a peripheralsurface at a distal end of femoral implant 12. The location is such thatleads 20 are exposed through most or all of a lower leg rotation. In atleast one exemplary embodiment, peg lugs 19 extend into an interiorsurface of femoral implant 12. The lateral view of femoral implant 12illustrates peg lugs 19 extending from the surface of femoral implant12. Femoral implant 12 is C-shaped having an outer surface that mimics anatural condyle surface. The interconnect is placed overlying orinterior to the internal surface of femoral implant 12 connecting peglugs 19 to leads 20.

Many neuro-stimulation procedures require precise positioning ofelectrical leads. Similarly, an orthopedic joint implant requiresprecise positioning of the prosthesis components to the skeletal systemcorresponding to location, distance, relational bone to bonepositioning, balance, and alignment. Integration of leads 20 into aprosthesis component takes advantage of this precise positioning withinthe body that is a very repeatable and consistent procedure. Thus,integration of leads 20 on the surface of a prosthetic component, orcomponents, or within a prosthetic components, enables accurateplacement of the leads automatically with the same high level ofaccuracy as the placement of the prosthesis itself. There is no addedsurgical time to incorporate the post-operative pain inhibitor since itis incorporated in the implant thereby minimizing stress on the patient.Moreover, this reduces cost because the device can be implementedwithout requiring the assistance of a neurosurgeon. Ultimately, thepatient benefits of less post operative pain (under user control) andfaster recovery are achieved with minimal impact to the complexity,cost, and length of the surgery.

Circuitry 44 can further comprise additional circuitry that is placed infemoral implant 12. Circuitry 44 can process a received signal fromcontroller 32 to support driving leads 20 to output a pulsed signalappropriate to stimulate a peripheral nerve fiber in proximity to leads20 to block a body generated pain signal. The pulsed signal output byleads 20 can be processed or modified in different ways. In a firstembodiment, processing by circuitry 44 is minimal with leads 20 directlyconnected to neuro-stimulator circuitry external to the patient througha transcutaneous lead. The neuro-stimulator circuitry can be located incontroller 32 or on or near the transcutaneous lead. In a secondembodiment, one or more topical leads having a transmitter that isconnected to neuro-stimulator circuitry external to the patient. Thetopical leads are affixed to the skin 1 of the patient in proximity tofemoral implant 12. Pulses of electrical energy corresponding to asignal provided to the peripheral nerve fiber are coupled wirelessly tocircuitry 44 integrated into the femoral component 12. In a thirdembodiment, circuitry 44 can further comprise a power source andneuro-stimulator circuitry to control pain under control of the patientcontroller 32. The neuro-stimulator circuitry is located in femoralimplant 12 and can generate appropriate waveforms under patient controlto stimulate the peripheral nerve fibers to reduce pain.

In at least one exemplary embodiment, circuitry 44 is integrated withinthe femoral component 12 and positioned within or underlying peg lugs19. A receiver circuit of circuitry 44 can be embedded within thefemoral component 12 to wirelessly couple electrical energy radiated byan external source, such as, but not limited to, an induction loop orantenna. The energy received by the induction loop or antenna can becoupled directly to transmitter circuitry of circuitry 44 that isprovided to leads 20 to be radiated to the peripheral nerve fiber.Circuitry 44 can further comprise energy storage capacity that includes,but is not limited to, a battery, capacitor, super capacitor,supercapacitor, ultra cap, ultra capacitor, ultracapacitor, or means ofcontinuous reception of external energy. The embedded receiver can becoupled to the energy storage capacity to power circuitry 44 and morespecifically neuro-stimulation circuitry in femoral implant 12. Theoutput of the neuro-stimulation circuitry is coupled to the leads 20 toprovide the pain blocking waveform to the peripheral nerve fiber.

Another variation is the integration of an intraosseous lead or leadsinto the tip or tips of the peg lugs 19. The intraosseous leads can beincluded in addition to the leads on the perimeter of femoral implant 12to supplement coupling of the stimulation signal to the peripheral nervefiber. Intraosseous leads can also be used in place of the leads 20 tooutput a signal that stimulates the peripheral nerve fiber. Theintraosseous leads are under the control of controller 32 as are leads20.

FIG. 8 is an illustration of components of a post-operative paininhibitor system 100 integrated into more than one prostheticcomponents. As mentioned previously, incorporating leads into anorthopedic implant component to stimulate peripheral nerve fibers forreducing pain is beneficial because of proximity to the operative fieldand peripheral nerve fibers as well as the precise positioning of thecomponent. There may be situations where patients require multiple jointprostheses to raise their quality of life. In such instances,post-operative pain inhibitor system can be used in conjunction witheach implanted component. In at least one exemplary embodiment, a singlepatient controller 32 can control each implanted component havingintegrated leads to affect body generated potentials in proximity toeach implanted region.

A leg is illustrated having both a hip implant and a knee implant. Theknee implant has been described in detail hereinabove. A hip replacementtypically comprises a cup 11, a bearing, and a femoral implant 13. In atleast one exemplary embodiment, cup 11 comprises metal or other materialof high strength. The surgeon reams out the acetabulum area of thepelvis to fit cup 11. The fitting of cup 11 requires precise positioningin the reamed out acetabulum and is typically a compression fitting. Thebearing is then fitted into cup 11 for providing a low friction low wearsurface in which a femoral head of femoral implant 13 is fitted. Thebearing typically comprises a polymer material such as ultra highmolecular weight polyethylene. In general, a predetermined amount ofsurface area of femoral head is in contact with the surface of bearingto minimize loading and wear on the material. The surgeon prepares femur2 to receive and retain femoral implant 13. Femoral implant 13 isfastened into a proximal end of femur 2. Femoral implant 13 comprises astrong lightweight material and typically comprises a metal or metalalloy. The hip and knee replacement components are selected to be formedof biologically compatible materials.

Femoral implant 12 and tibial implant 14 of the knee implant includecircuitry and leads to stimulate peripheral nerve fibers in proximity tothe operative field of the knee. Similarly, femoral implant 13 includescircuitry and leads to stimulate peripheral nerve fibers in proximity tothe operative field of the hip. As disclosed above, controller 32 isoperatively coupled to provide a signal to the leads of femoral implant13, femoral implant 12, and tibial implant 14. Controller 32 furtherprovides patient control of the signal provided to each implant therebyallowing the patient to tailor the signal waveform to minimize perceivedpain in the knee and hip regions. The anteroposterior view illustratesthe relative positions of cup 11, femoral implant 13, femoral implant12, and tibial implant 14. The example illustrates post-operative paininhibitor system 100 having more than one active component but is notlimited to multiple device applications.

FIG. 9 is a lateral view of post-operative pain inhibitor system 100 inaccordance with an exemplary embodiment. The lateral view illustratespositioning of the post-operative pain inhibitor system 100 in relationto the leg, operative field, and joint implant 10. Controller 32 isattached by a belt to the waist of the patient. Controls of controller32 are easily accessible to the patient to modify the signals output byneuro-stimulator circuitry residing therein. The lateral viewillustrates femoral implant 13 in a hip region. It also illustratesfemoral implant 14 and tibial implant 12 in the knee region. Theimplants have leads that are exposed in periodic spacingcircumferentially around the implant to maximize signal coverage.Alternatively, the leads can be placed in specific locations that are inproximity to a peripheral nerve.

FIG. 10 is an illustration of hip prosthesis 17 in accordance with anexemplary embodiment. Each leg has femoral implant 13 coupled to aproximal end of femur 2. Each femoral implant 13 includes leads forcoupling to a peripheral nerve fiber in proximity to the joint implant.As disclosed hereinabove, femoral implant 13 can house circuitry and apower supply. Controller 32 is coupled to the leads of each femoralimplant for providing a signal. The signal can be controlled by thepatient. The leads of each implant output the signal to block bodygenerated action potential in the peripheral nerve corresponding to apain signal. Controller 32 can modify the signal under user control toeach femoral implant 13 to a waveform that minimizes perceived pain foreach leg in proximity to the hip region.

In general, an invasive procedure such as hip surgery causes chemicalsin the body to be released due to the incision and subsequent damage tothe surrounding tissue as the bone is modified and the implants put inplace. The bodily generated chemicals greatly sensitize the localnociceptors causing substantial pain to the patient. Gate theory impliesthat the bodily generated action potentials propagating to theperipheral nerve fibers can be opened or closed. Post-operative paininhibitor system 100 reduces the propagation of the signals bystimulating the peripheral nerve fibers to close the gate. As mentionedpreviously, the signal coupled to the peripheral nerve fibers are lowcurrent pulses. In general, a typical frequency of the pulses are in therange of 100-200 Hz.

The circuitry placed in femoral implant 13 comprises a power source,such as a battery and electronic circuitry to energize electrical leadsor to radiate electrical stimuli into the field of stimulation. Thelatter circuitry is referred to as a transmitter. Wireless nervestimulators can be powered by receiving externally generated electricalenergy as input to the transmitter. This receiving circuitry is referredto as a receiver. The provided energy can be continuous or intermittent.If the energy is provided intermittently, a capacity for storingelectrical energy can be used such as a battery, capacitor, or inductor.

FIG. 11 is an illustration of a tibial implant 14 in accordance with anexemplary embodiment. Tibial implant 14 is a support and retainingstructure for the insert. Leads 21, 22, 24, and 28 are integrated intotibial implant 14. The anteroposterior and lateral views of the tibialcomponent illustrates the placement of the leads 21, 23, 24, and 28 thatare exposed on the perimeter of the tibial component 14. The leadscouple to neuro-stimulation circuitry in one of tibial implant 14, ahousing attached to skin 1, or in controller 32. Leads 21, 23, 24, and28 provide signals to peripheral nerve fibers to block body generatedaction potentials under patient control via controller 32. Circuitry 44can be integrated in many locations within the tibial implant 14. In oneembodiment, circuitry 44 is housed in stem 17 of tibial implant 14.

In at least one exemplary embodiment, an intraosseous lead or leads arepositioned on or integrated within the tip (not shown) of the stem 17 ofthe tibial implant 14. In one embodiment, the intraosseous leads are inaddition to leads 21, 23, 24, 28 on the perimeter of the tibialcomponent 14. In a second embodiment the intraosseous leads can be usedin place of one or more leads 21, 23, 24, and 28. The intraosseous leadsprovide a conductive field of operation that provides effectiveperipheral nerve stimulation.

FIG. 12 is an illustration of a femoral implant 13 and cup implant 11 inaccordance with an exemplary embodiment. Cup implant 11 is also known asan acetabulum component. The anteroposterior view of femoral implant 13illustrates exposed leads positioned circumferentially and in differentareas of implant 13. The leads are connected by wire to circuitry 44that can be formed in, internal to, or external to femoral implant 13.As shown, wires are placed along the sides of the stem 18 of the femoralimplant 13 or integrated within the perimeter of the stem 18 of thefemoral implant 13 of the hip prosthesis. In a non-limiting example,circuitry 44 can be placed in a tip region of femoral implant 13.Circuitry 44 can include a power source and a transmitter/receiver.Circuitry 44 in conjunction with the exposed leads generates a field ofoperation that provides effective peripheral nerve stimulation. Thenerve stimulation can be modified using patient controller 32.

The lateral view of cup 11 illustrates the placement of leads 20positioned on or integrated into the perimeter of the cup 11. Circuitry44 can be integrated in many locations within the cup 11. In anon-limiting example, circuitry 44 is shown in a central region of cup11.

A further variation includes intraosseous lead or leads positioned on orintegrated within the tip of stem 18 of the femoral component 13. In afirst embodiment the intraosseous lead or leads are addition to theleads on the perimeter of femoral implant 13. In a second embodiment,intraosseous leads are used solely to create an operative field thatprovides effective peripheral nerve fiber stimulation in conjunctionwith external patient controller 32.

FIG. 13 depicts an exemplary diagrammatic representation of a machine inthe form of a computer system 1300 within which a set of instructions,when executed, may cause the machine to perform any one or more of themethodologies discussed above. In some embodiments, the machine operatesas a standalone device. In some embodiments, the machine may beconnected (e.g., using a network) to other machines. In a networkeddeployment, the machine may operate in the capacity of a server or aclient user machine in server-client user network environment, or as apeer machine in a peer-to-peer (or distributed) network environment.

The machine may comprise a server computer, a client user computer, apersonal computer (PC), a tablet PC, a laptop computer, a desktopcomputer, a control system, a network router, switch or bridge, or anymachine capable of executing a set of instructions (sequential orotherwise) that specify actions to be taken by that machine. It will beunderstood that a device of the present disclosure includes broadly anyelectronic device that provides voice, video or data communication.Further, while a single machine is illustrated, the term “machine” shallalso be taken to include any collection of machines that individually orjointly execute a set (or multiple sets) of instructions to perform anyone or more of the methodologies discussed herein.

The computer system 1300 may include a processor 1302 (e.g., a centralprocessing unit (CPU), a graphics processing unit (GPU, or both), a mainmemory 1304 and a static memory 1306, which communicate with each othervia a bus 1308. The computer system 1300 may further include a videodisplay unit 1310 (e.g., a liquid crystal display (LCD), a flat panel, asolid state display, or a cathode ray tube (CRT)). The computer system1300 may include an input device 1312 (e.g., a keyboard), a cursorcontrol device 1314 (e.g., a mouse), a disk drive unit 1316, a signalgeneration device 1318 (e.g., a speaker or remote control) and a networkinterface device 1320.

The disk drive unit 1316 can be other types of memory such as flashmemory and may include a machine-readable medium 1322 on which is storedone or more sets of instructions (e.g., software 1324) embodying any oneor more of the methodologies or functions described herein, includingthose methods illustrated above. The instructions 1324 may also reside,completely or at least partially, within the main memory 1304, thestatic memory 1306, and/or within the processor 1302 during executionthereof by the computer system 1300. The main memory 1304 and theprocessor 1302 also may constitute machine-readable media.

Dedicated hardware implementations including, but not limited to,application specific integrated circuits, programmable logic arrays andother hardware devices can likewise be constructed to implement themethods described herein. Applications that may include the apparatusand systems of various embodiments broadly include a variety ofelectronic and computer systems. Some embodiments implement functions intwo or more specific interconnected hardware modules or devices withrelated control and data signals communicated between and through themodules, or as portions of an application-specific integrated circuit.Thus, the example system is applicable to software, firmware, andhardware implementations.

In accordance with various embodiments of the present disclosure, themethods described herein are intended for operation as software programsrunning on a computer processor. Furthermore, software implementationscan include, but not limited to, distributed processing orcomponent/object distributed processing, parallel processing, or virtualmachine processing can also be constructed to implement the methodsdescribed herein.

The present disclosure contemplates a machine readable medium containinginstructions 1324, or that which receives and executes instructions 1324from a propagated signal so that a device connected to a networkenvironment 1326 can send or receive voice, video or data, and tocommunicate over the network 1326 using the instructions 1324. Theinstructions 1324 may further be transmitted or received over a network1326 via the network interface device 1320.

While the machine-readable medium 1322 is shown in an example embodimentto be a single medium, the term “machine-readable medium” should betaken to include a single medium or multiple media (e.g., a centralizedor distributed database, and/or associated caches and servers) thatstore the one or more sets of instructions. The term “machine-readablemedium” shall also be taken to include any medium that is capable ofstoring, encoding or carrying a set of instructions for execution by themachine and that cause the machine to perform any one or more of themethodologies of the present disclosure.

The term “machine-readable medium” shall accordingly be taken toinclude, but not be limited to: solid-state memories such as a memorycard or other package that houses one or more read-only (non-volatile)memories, random access memories, or other re-writable (volatile)memories; magneto-optical or optical medium such as a disk or tape; andcarrier wave signals such as a signal embodying computer instructions ina transmission medium; and/or a digital file attachment to e-mail orother self-contained information archive or set of archives isconsidered a distribution medium equivalent to a tangible storagemedium. Accordingly, the disclosure is considered to include any one ormore of a machine-readable medium or a distribution medium, as listedherein and including art-recognized equivalents and successor media, inwhich the software implementations herein are stored.

Although the present specification describes components and functionsimplemented in the embodiments with reference to particular standardsand protocols, the disclosure is not limited to such standards andprotocols. Each of the standards for Internet and other packet switchednetwork transmission (e.g., TCP/IP, UDP/IP, HTML, HTTP) representexamples of the state of the art. Such standards are periodicallysuperseded by faster or more efficient equivalents having essentiallythe same functions. Accordingly, replacement standards and protocolshaving the same functions are considered equivalents.

The illustrations of embodiments described herein are intended toprovide a general understanding of the structure of various embodiments,and they are not intended to serve as a complete description of all theelements and features of apparatus and systems that might make use ofthe structures described herein. Many other embodiments will be apparentto those of skill in the art upon reviewing the above description. Otherembodiments may be utilized and derived therefrom, such that structuraland logical substitutions and changes may be made without departing fromthe scope of this disclosure. Figures are also merely representationaland may not be drawn to scale. Certain proportions thereof may beexaggerated, while others may be minimized. Accordingly, thespecification and drawings are to be regarded in an illustrative ratherthan a restrictive sense.

By now it should be appreciated that various embodiments of apost-operative pain inhibitor system has been described. In particular,the PPI provides substantial benefit in reducing post-surgical painafter a joint replacement. Reducing pain alleviates patient stress andcan accelerate the rehabilitation process. Post-operative paininhibitors may be applied to a wide range of surgeries and implantedmedical devices. These include shoulder, elbow, wrist, hand, spine, andankle surgeries and prosthetic devices.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

What is claimed is:
 1. A post-operative pain inhibitor system configuredfor post-operative treatment of an implant comprising: an implantcomponent having an electrode where the electrode is configured todeliver energy pulses, where the energy pulses are either emitted fromor received by the electrode and where emitted energy pulses from theelectrode are configured to stimulate peripheral nerve fibers to blockor inhibit a pain signal.
 2. The system as recited in claim 1 where theimplant component is a prosthetic hip component and further comprises atleast one of a femoral implant, a bearing, or a cup.
 3. The system ofclaim 2 further including a controller coupled to the at least oneelectrode configured to modify at least one of pulse width, pulserepetition rate, or pulse amplitude of the energy pulse.
 4. The systemof claim 3 where the controller is configured to be under patientcontrol.
 5. The system of claim 3 further including at least onepercutaneous electrode.
 6. The system of claim 3 further including atleast one subcutaneous electrode.
 7. The system of claim 3 furtherincluding at least one intraosseus electrode coupled to the controller.8. The system of claim 3 further including at least one topicalelectrode coupled to the controller.
 9. A post-operative pain inhibitorsystem configured for post-operative treatment of a hip joint implantcomprising: a prosthetic hip component having at least one electrodewhere the at least one electrode is configured to deliver energy pulses,where the prosthetic hip component comprises at least one of a femoralimplant, a bearing, or a cup; a controller coupled to the at least oneelectrode configured to modify at least one of pulse width, pulserepetition rate, or pulse amplitude of the energy pulse; and one or moresensors configured to couple to the controller to monitor at least oneof temperature, perspiration, inflammatory markers, electromyogramsignals, and swelling and where emitted energy pulses from the at leastone electrode are configured to stimulate peripheral nerve fibers toblock or inhibit a pain signal.
 10. A post-operative pain inhibitorsystem configured for post-operative treatment of an implanted hip jointcomprising: a transmitter; a power source coupled to the transmitter; anelectrode configured to couple to the transmitter where the electrode isin proximity to the implanted joint and where the electrode isconfigured to deliver energy pulses; and a prosthetic hip componentwhere one of the transmitter or power source is housed in the prostheticcomponent and where emitted energy pulses from the electrode areconfigured to stimulate peripheral nerve fibers to block or inhibit apain signal.
 11. The system of claim 10 further including a receivercoupled to the power source.
 12. The system of claim 11 where thereceiver is configured to receive energy wirelessly.
 13. The system ofclaim 12 where the prosthetic component further comprises the at leastone electrode.
 14. The system of claim 10 further including a controllerconfigured to be coupled to at least one electrode where the controlleris configured to modify at least one of the pulse width, pulserepetition rate, pulse shape, or pulse amplitude.
 15. The system ofclaim 10 further including further including at least one electrodeconfigured to subcutaneously couple in proximity to the operative field.16. The system of claim 10 further including at least one electrodeconfigured to percutaneously couple in proximity to the operative field.17. The system of claim 10 further including at least one electrodeconfigured to intraosseously couple in proximity to the operative field.18. A post-operative pain inhibitor system configured for post-operativetreatment of a hip joint implant comprising: a controller; a prosthetichip component; an electrode where the electrode is configured to attachto skin in proximity to the component, where the controller isconfigured to couple to the electrode, and where the at least oneelectrode is configured to deliver energy pulses; a transmitterconfigured to couple to the electrode; and a power source coupled to thetransmitter where one of the transmitter or power source is housed inthe prosthetic hip component and where emitted energy pulses from theelectrode are configured to stimulate peripheral nerve fibers to blockor inhibit a pain signal.
 19. The system of claim 18 further including areceiver coupled to the power source where the receiver is configured toreceive energy wirelessly.
 20. The system of claim 18 further includinga percutaneous electrode configured to couple in proximity to theoperative field where the controller is configured to coupled to thepercutaneous electrode and where the percutaneous electrode isconfigured to deliver energy pulses.